CBSE Class 11 Physics Revision Notes

CBSE Class 11 Physics Revision Notes summarise the major concepts, laws, formulas and numerical methods covered across the current syllabus. They help CBSE students revise mechanics, properties of matter, thermal physics, oscillations and waves in a structured form.

Physics explains motion, forces, energy, matter, heat and waves through measurable quantities and mathematical relations. Class 11 introduces these ideas through observations, laws, graphs, experiments and numerical problems.

These CBSE Class 11 Physics Revision Notes follow the current 2026–27 chapter sequence. Use them to revise important concepts, recall formulas and understand the physical meaning behind each equation.

Key Takeaways

• 14 chapters: The current Class 11 Physics syllabus begins with Units and Measurements and ends with Waves.
• Two textbook parts: Part I covers Chapters 1 to 7, while Part II covers Chapters 8 to 14.
• 70 marks: The theory examination carries 70 marks, along with 30 marks for practical assessment.
• Core approach: Physics revision requires concepts, SI units, diagrams, graphs, derivations and numerical application.

Access Class 11 Physics Notes in 30 Minutes

Revise the syllabus in three parts:

• First 10 minutes: Units, motion, vectors, Newton’s laws, work, energy and power
• Next 10 minutes: Rotational motion, gravitation, solids, fluids and thermal properties
• Final 10 minutes: Thermodynamics, kinetic theory, oscillations, waves and important formulas

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Chapter-Wise CBSE Class 11 Physics Notes

The current Class 11 Physics NCERT textbook is divided into two parts. Part I develops mechanics, while Part II covers properties of matter, heat, gases, oscillations and waves.

Physics Part I: Mechanics and Gravitation

Physics Part I contains the first seven chapters. These chapters build the mathematical and conceptual base needed for later topics.

Chapter 1: Units and Measurements

Measurement compares a physical quantity with a standard unit. The SI system provides accepted units for length, mass, time and other fundamental quantities.

Students study significant figures, dimensions and errors in measurement. Dimensional analysis checks whether both sides of a physical equation have the same dimensions.

Important ideas include:

• Fundamental and derived quantities
• SI base units
• Least count
• Accuracy and precision
• Absolute, relative and percentage errors
• Significant figures
• Dimensional formulae

For percentage error:

Percentage error = Absolute error/Measured value × 100

Dimensions of velocity:

[M⁰L¹T⁻¹]

Dimensions of force:

[M¹L¹T⁻²]

Chapter 2: Motion in a Straight Line

Motion in a straight line describes one-dimensional motion. Position changes with time along a fixed line.

Distance gives the total path travelled. Displacement gives the change between initial and final positions.

Important quantities are:

• Position
• Distance
• Displacement
• Speed
• Velocity
• Acceleration

Average velocity:

Average velocity = Total displacement/Total time

Acceleration:

a = (v − u)/t

For uniformly accelerated motion:

v = u + at

s = ut + ½at²

v² = u² + 2as

Graphs of position, velocity and acceleration help describe motion visually.

Chapter 3: Motion in a Plane

Motion in a plane involves two dimensions. Vectors are used because direction becomes important.

A vector has both magnitude and direction. A scalar has magnitude only.

Examples of vectors include displacement, velocity, acceleration and force. Distance, speed, mass and time are scalars.

For a vector A:

A = Ax i + Ay j

Magnitude:

|A| = √(Ax² + Ay²)

The chapter also covers projectile motion. Horizontal and vertical motions are studied separately.

Time of flight:

T = 2u sin θ/g

Maximum height:

H = u² sin² θ/2g

Horizontal range:

R = u² sin 2θ/g

Chapter 4: Laws of Motion

Newton’s laws explain the relation between force and motion.

The first law describes inertia. A body remains at rest or in uniform motion unless an external force acts on it.

The second law relates force to momentum:

F = dp/dt

For constant mass:

F = ma

The third law states that every action has an equal and opposite reaction.

Linear momentum is:

p = mv

For an isolated system:

Total momentum before collision = Total momentum after collision

The chapter also covers friction, equilibrium and motion on inclined surfaces.

Chapter 5: Work, Energy and Power

Work is done when force produces displacement.

For a constant force:

W = Fs cos θ

Kinetic energy is the energy of motion:

K = ½mv²

Potential energy depends on position or configuration. Near Earth’s surface:

U = mgh

The work-energy theorem states:

Net work done = Change in kinetic energy

Power measures the rate of doing work:

P = W/t

For force F and velocity v:

P = F · v

Mechanical energy remains conserved when only conservative forces act.

Chapter 6: System of Particles and Rotational Motion

This chapter extends motion from a single particle to systems and rigid bodies.

The centre of mass represents the effective position of the mass of a system.

For two particles:

xcm = (m1x1 + m2x2)/(m1 + m2)

Torque is the turning effect of force:

τ = r × F

Angular momentum is:

L = r × p

For a rigid body rotating about a fixed axis:

L = Iω

Rotational kinetic energy:

K = ½Iω²

Moment of inertia depends on mass distribution and the selected axis of rotation.

Chapter 7: Gravitation

Every particle attracts every other particle through gravitational force.

Newton’s law of gravitation is:

F = Gm1m2/r²

Acceleration due to gravity near Earth is:

g = GM/R²

Gravitational potential energy is:

U = −GMm/r

Orbital velocity near a planet is:

vo = √(GM/r)

Escape speed from Earth’s surface is:

ve = √(2GM/R)

Therefore:

ve = √2vo

The chapter also covers variation in g, gravitational potential, satellites and Kepler’s laws.

Physics Part II: Matter, Heat, Oscillations and Waves

Physics Part II begins with the mechanical properties of matter. It then develops heat, gas behaviour and periodic motion.

Chapter 8: Mechanical Properties of Solids

A solid changes shape or size when an external force acts on it. Elasticity describes its ability to regain the original form.

Stress is restoring force per unit area:

Stress = F/A

Strain is the fractional change in dimension.

Longitudinal strain:

Strain = ΔL/L

Hooke’s law states that stress is proportional to strain within the elastic limit.

Young’s modulus is:

Y = Longitudinal stress/Longitudinal strain

The chapter also covers bulk modulus, shear modulus and stress-strain curves.

Chapter 9: Mechanical Properties of Fluids

Fluids include liquids and gases. They can flow and exert pressure on surfaces.

Pressure is:

P = F/A

Pressure at depth h is:

P = P0 + ρgh

Pascal’s law explains the transmission of pressure through a confined fluid.

Archimedes’ principle states that buoyant force equals the weight of displaced fluid.

The continuity equation is:

A1v1 = A2v2

Bernoulli’s equation is:

P + ½ρv² + ρgh = Constant

The chapter also covers viscosity, terminal velocity, surface tension and capillarity.

Chapter 10: Thermal Properties of Matter

Temperature describes the thermal state of a body. Heat is energy transferred because of a temperature difference.

The relation between Celsius and Kelvin scales is:

T(K) = t(°C) + 273.15

Linear expansion is:

ΔL = αLΔT

Heat required to change temperature is:

Q = mcΔT

Heat required for change of state is:

Q = mL

Heat transfer occurs through:

• Conduction
• Convection
• Radiation

Newton’s law of cooling describes the rate at which a body loses heat to its surroundings.

Chapter 11: Thermodynamics

Thermodynamics studies heat, work, temperature and internal energy.

The zeroth law establishes the concept of thermal equilibrium.

The first law is:

ΔQ = ΔU + ΔW

Here:

• ΔQ is heat supplied
• ΔU is change in internal energy
• ΔW is work done by the system

Important thermodynamic processes include:

• Isothermal process
• Adiabatic process
• Isochoric process
• Isobaric process
• Cyclic process

The second law gives the natural direction of heat flow and limits the conversion of heat into work.

Chapter 12: Kinetic Theory

Kinetic theory explains the behaviour of gases through molecular motion.

An ideal gas follows:

PV = nRT

Pressure of an ideal gas is related to molecular speed:

P = ⅓ρvrms²

The root mean square speed is:

vrms = √(3RT/M)

The average translational kinetic energy per molecule is:

K = 3/2 kT

The chapter also covers degrees of freedom, law of equipartition of energy, specific heat capacity and mean free path.

Chapter 13: Oscillations

Oscillatory motion repeats around a mean position.

A periodic motion repeats after equal intervals of time. Simple harmonic motion occurs when restoring force is proportional to displacement and directed towards the mean position.

The displacement equation is:

x = A cos (ωt + ϕ)

Velocity is:

v = ±ω√(A² − x²)

Acceleration is:

a = −ω²x

For a spring-mass system:

T = 2π√(m/k)

For a simple pendulum:

T = 2π√(l/g)

Total energy in SHM is:

E = ½mω²A²

Chapter 14: Waves

A wave transfers energy through a medium without permanent transfer of matter.

Mechanical waves may be transverse or longitudinal.

The general relation is:

v = νλ

Here:

• v is wave speed
• ν is frequency
• λ is wavelength

A progressive wave may be represented as:

y = A sin (kx − ωt + ϕ)

Wave number:

k = 2π/λ

Angular frequency:

ω = 2πν

The principle of superposition explains the combined displacement caused by overlapping waves.

Beat frequency is:

νbeat = |ν1 − ν2|

The chapter also covers reflection of waves and standing-wave patterns.

Major Concepts Covered in Class 11 Physics Notes

Class 11 Physics important concepts can be grouped according to the physical systems they describe. This helps connect chapters instead of revising each one separately.

Measurement and Motion

Units and Measurements provides the language of Physics. Motion chapters then use this language to describe position, velocity and acceleration.

Graphs, vectors and dimensions appear throughout the syllabus. An error in units or direction can change the complete numerical answer.

Forces, Energy and Rotation

Laws of Motion explains why velocity changes. Work, Energy and Power studies the effect of force over displacement.

Rotational Motion extends these ideas through torque, angular momentum and moment of inertia.

Gravitation and Properties of Matter

Gravitation explains attraction between masses. The chapters on solids and fluids explain how matter responds to force.

These chapters use force, pressure, energy and equilibrium in different physical situations.

Heat and Thermodynamics

Thermal Properties of Matter describes temperature changes and heat transfer.

Thermodynamics studies heat, work and internal energy at the macroscopic level. Kinetic Theory connects these ideas with molecular motion.

Oscillations and Waves

Oscillations describe repeated motion around a mean position. Waves describe the movement of disturbances through a medium.

Frequency, period, angular frequency and phase appear in both chapters.

Important Class 11 Physics Formulas for Quick Revision

Use formulas only after identifying the quantities, conditions and SI units involved.

CBSE Class 11 Physics Unit-Wise Marks Distribution

The theory paper carries 70 marks. The current distribution groups related chapters into five marks blocks.

How to Use Class 11 Physics Revision Notes for Numericals

Class 11 Physics exam preparation depends on concept selection before calculation. A formula gives the right answer only when its conditions match the question.

Use this order for numerical problems:

1. Write the given quantities.
2. Convert every value into SI units.
3. Identify the required quantity.
4. Draw a diagram where needed.
5. Select the relevant law or formula.
6. Substitute values with units.
7. Check dimensions and sign.
8. Write the final answer with the correct unit.

For vector questions, direction must be included. For graph questions, check what the slope and area represent.

In motion graphs:

• Slope of position-time graph gives velocity.
• Slope of velocity-time graph gives acceleration.
• Area under velocity-time graph gives displacement.

In rotational questions, identify the axis before using moment of inertia. In thermodynamics, check whether work is done by or on the system.